Fuels used in today's automotive engines cause deposits to be formed during combustion. Such deposits collect on parts of the combustion chamber including valves, spark plugs, cyclinder heads and walls. Formation of these deposits can result in increased exhaust emissions.
Cyclopentadienyl manganese compounds are excellent antiknocks in gasolines used to operate internal combustion engines and have proven to be especially beneficial in solving some of the problems present when low-lead or lead-free gasolines are used with internal combustion engines. Use of such compounds as antiknocks is described in U.S. Pat. Nos. 2,818,417, 2,839,552 and 3,127,351 all incorporated herein by reference.
The use of various ethers in fuels to reduce knocking of the fuel or to reduce carbon monoxide emissions is also known. U.S. Pat. No. 2,409,746 discloses the use of certain asymmetrical dialkyl ethers, particularly methyl tetriary butyl ether in motor fuel to reduce the knocking of the fuel in supercharged gasoline engines. Roselle discloses in U.S. Pat. No. 2,046,243 the use of branched ethers, particularly isopropyl ether, in motor fuel to reduce knocking of the engine. U.S. Pat. No. 3,820,962 discloses a fuel additive composition comprising a major amount of white oil and minor amounts of a dialkyl ether and oil of orange effective for reducing carbon monoxide emissions from the combustion of a hydrocarbon fuel in an internal combustion engine. U.S. Pat. No. 2,952,612 discloses a process for improving the effectiveness of high octane materials such as saturated alkyl ethers in combination with catalytically cracked gasoline in automotive fuels.